A storage system is a processing system adapted to store and retrieve data on behalf of one or more client processing systems (“clients”) in response to external input/output (I/O) requests received from clients. A storage system can provide clients with a file-level and/or a block-level access to data stored in a set of mass storage devices, such as magnetic or optical storage disks.
A hard disk drive (HDD) or a disk is a digitally encoded non-volatile storage device, which stores data on rapidly rotating platters with magnetic surfaces. A spindle is a motor responsible for turning the platters, allowing the hard disk drive to operate. Each disk requires energy to rotate a spindle and move platters. For disk drives, electrical power consumption currently contributes to 20% of the total cost of ownership of a data center. As the number of disks in the storage system increases, the amount of energy required to operate the storage system increases. Over the past years, storage capacity of a typical storage system has risen from 3 terabyte (TB) to 50 TB in size. This increasing need for data represents a rising power usage.
Accordingly, what is needed is a mechanism for reducing power consumption in a storage system.